Sleep-related cognitive problems can result in accidents, deficient job and work performance, poor decision making, and other serious problems. Previous research supports the general conclusion that sleep problems influence cognitive functioning, but evidence also indicates sleep problems affect some cognitive functions more than others. However, specific patterns of impairments are inconsistent across studies, possibly because of less than optimal individual cognitive measures. Moreover, the field lacks a systematic analysis of developmental patterns of general and specific Sleep problems and their cognitive covariates and sequelae. The specific aims of this project are to (1) identify developmental patterns in sleep problems; (2) specify the etiology of sleep problems, including genetic and environmental contributions to stability and change; and (3) determine the effect of developmental and concurrent sleep problems on different cognitive functions. These goals will be addressed through application of statistical techniques, not previously applied to these issues, to existing longitudinal data from a large-scale study of 462 twin pairs examined from infancy through early adulthood. Specifically, we will use latent class growth curve models of parent-rated sleep problems from ages 4 to 16 to explore the development of sleep problems and identify different patterns (e.g., persistent vs. transient). We will then apply genetic models of these developmental patterns as well as problems at individual time points to specify the etiology of these problems. Finally, we will examine the cognitive outcomes of developmental problems as well as recent self-ratings of sleep habits, using latent- variable cognitive ability outcome measures of multiple separable executive functions and other cognitive abilities. We will also examine the effect of sleep problems on teacher-rated attention and thought problems throughout development. These proposed analyses will result in more comprehensive and powerful models of sleep problems and cognitive function. [unreadable] [unreadable] [unreadable]